In our Swedish patent No 9403168-9 (equivalent to WO 96/09505 and U.S. Pat. No. 5,810,249), there is described how to make snow crystals in two steps. In a first step, nuclei are created in the outer periphery of the air flow, in that extremely fine drops of water are sprayed through atomizing nozzles of the back zone of the nose cone. In a second step, the nuclei are mixed and thereby formed with atomized water drops which are ejected into the air flow passing through the snow making machine from the ordinary water nozzles of the snow making machine, thereby forming a plume of water drops which are mixed with the nuclei in a turbulent air flow.
A problem has been that a part of the water drops which is ejected from the nozzles falls to the ground in an only partly frozen or even non-frozen condition thereby forming an unwanted layer of ice on the ground. This problem is increasingly noticeable the higher the temperature of the ambient air is. Until now it has not been possible, in practice, to make artificial snow if the temperature of the ambient air is higher than about -3.degree. C. to -2.5.degree. C., and even at such theoretically possible temperatures of the ambient air there have been problems to freeze all water drops ejected from the water nozzles. In many cases it has not been considered practically and economically possible to make artificial snow at higher temperatures than -3.degree. C. to -4.degree. C.
For having the water drops distributing themselves in an optimum way in the air flow of the snow making machine, and for having the snow making machine produce the greatest possible amount of snow crystals, it has been shown suitable to form the snow making machine with several rings of water distribution nozzles arranged axially on line after each other adjacent the outlet end of the snow making machine. Today there are generally used at least three nozzle rings, and even as much as six nozzle rings.